This is a portion of the Material Safety Data Sheet for deionized (DI) water. DI water is basically purified water, in other words, pure H2O. If you look closely, the recommended first aid measure for eye contact with water is to "Flush eyes with water as a precaution. Get medical attention immediately if symptoms occur." In other words, if you get water in your eyes, you should flush it with water. All joking aside, water is an eye irritant if an eye is exposed for some time. On the other hand, the first aid measure for skin contact is similarly "Rinse with water." This just always amused me.